Study On Rapid Solidification And Microstructure Of Fe-Cu Phase Separation Alloy

Under normal solidification conditions, the solid state structure of phase separation alloy may be stratified by gravity, so that its industrial application is limited. With the development of science and technology, it is possible to make the application of this kind of material by rapid solidification, which can be used to make the material different from the normal cooling condition. At present in electronic packaging materials and bearing materials are applied to the phase separation alloy. In recent years, more and more researcher pay their attention on phase separation alloys. Fe and Cu with excellent performance and low cost characteristics, coupled with Fe-Cu in the conventional cooling prone segregation phenomenon, so the Fe-Cu phase separation of the alloy preparation and research has the engineering and scientific significance. Fe-Cu phase separation alloy was obversed by suction casting, spinning and rapid solidification mode prepared Fe-Cu based alloy phase separation, throught SEM, DSC, XRD and other testing methods to know the formation mechanism of phase separation.1、Study on Fe-Cu alloy phase separation process and microstructure.The rapid solidification process of FesoCu2o alloy, Fe6oCu4o, FesoCuso prepared by phase separation, microstructure of the three components were observed and found that with the increase of Cu content, the alloy system experienced no phase separation to incomplete phase separation and phase separation. The second phase separation occured in Fc60Cu40 and Fe50Cu50, in order to reduce the interfacial energy, the bigger Fe-rich ball annexation the small Fe-rich ball. Throught SEM observationin the Fe8oCu2o alloy, with the increase of cooling rate, the volume fraction of Fe-rich and Cu-rich dendrite grain size decreases with the increase of undercooled; the DSC show that the phase separation temperature (TseP) and y-Fe start solidification temperature (Tγ),the temperature difference between Tsep and Ty (Tsep-TY) can express phase separation degree.2、The effect of Cu addition on Fe78Si9B13 to glass forming ability and performance.Increasing the atom percent of Cu to Fe78-xSi9B13Cux decreased the glass formation ability (GFA) of the alloy. When the Cu is up to 10%, Fe78-xSi9B13Cux alloy occur Cu-rich phase and Fe-rich phase separation. When Cu addition amount to less than 10%, due to the precipitation of Cu phase is solid solution in the Fe78-xSi9B13Cux, so it did not find Cu-rich phase and Fe-rich phase separation. When the percent content of element Cu increases, spray casting alloy bar and ribbons appeared obvious Cu rich phase and Fe rich phase separation. The Cu-rich phase and Fe-rich phase had show soft zone and hard zone, the hardness of Cu-rich is 110HV and Fe-rich is 660HV.The different soft and hard area increased the toughness of the material and improve the material application space.3、The effect of Fe to Cu64-xZr36Fex of glass forming ability.When the atom percent of Fe less than 1%, the GFA of Cu64-xZr36Fex alloy was bigger than Cu64Zr36; when the atom percent of Fe was more than 1%, as for positive effect to alloy, so that that the GFA of Cu64-xZr36Fex decreased. Observationing micro structure of Cu64-xZr36Fex did not find crystalline phase exists, because of the main crystal phase (Zr-Fe)-B2 phase was dissolved in the (Cu-Zr)-B2.